“THE  PRIMARY  DECOMPOSITION  PRO- 
DUCTS OF  PURE  CELLULOSE  AND 
CELLULOSIC  RESIDUES  OF 
WOOD  AND  COAL” 

BY 


HARLEY  LILLARD  KNAUER 


THESIS 


FOR  THE 


DEGREE  OF  BACHELOR  OF  SCIENCE 


CHEMICAL  ENGINEERING 


COLLEGE  OF  LIBERAL  ARTS  AND  SCIENCES 


UNIVERSITY  OF  ILLINOIS 


Digitized  by  the  Internet  Archive 
in  2016 


https://archive.org/details/primarydecomposiOOknau 


/922 
K 72 


UNIVERSITY  OF  ILLINOIS 


THIS  IS  TO  CERTIFY  THAT  THE  THESIS  PREPARED  UNDER  MY  SUPERVISION  BY 


ENTITLED. 


IS  APPROVED  BY  ME  AS  FULFILLING  THIS  PART  OF  THE  REQUIREMENTS  FOR  THE 


Approved  :. 


ACTING  HEAD  OF  DEPARTMENT  OF  ..CHEMISTRY. 


ACEH0V7LEDGMEKT 


I take  this  opportunity  to  thank  Dr.  T.  E.  Layng  for  the  valuable  sug- 
gestions and  assistance  which  I received  from  him  during  the  course  of  this  inves- 
tigation. 


. 


Table  of  Contents 


I.  Introduction. 

1.  Purpose  of  the  Investigation  . 1 

2.  Historical  . 1 

2.  Outline  of  the  Investigation  .......  4 

II.  Experimental . 

1.  Apparatus  •••.••• 5 

2.  Operation  6 

3.  Determination  and  Analysis  of  Products.  ...  7 

4.  Preparation  of  Materials  8 

III*  Results. 

1.  Tables  and  graphs 10 

2.  Discussion  of  results 16 

17.  Summary  and  Conclusions .19 


THE  PRIMARY  DECOMPOSITION  PRODUCTS  OF  PURE  CELLULOSE 


AND  CELLULOSIC  RESIDUES  OF  WOOD  AND  COAL 
I.  Introduction 

1.  Purpose  of  the  investigation. 

The  purpose  of  this  investigation  has  been  to  determine  the  primary  dec- 
omposition products  of  pure  cellulose  and  the  cellulosic  derivatives  of  wood  and 
coal  at  succesive  temperatures  from  250°  - 4i50°  C. 

2.  Historical. 

Coal,  according  to  the  most  prominent  investigators  is  made  up  of  three 
main  classes  of  constituents,  namely,  cellulosic,  resinic,  and  nitrogen-bearing 
protein.  When  coal  is  carbonized  it  gives  off  gases  such  as:  COg,  CO,  H^,  CH4, 
etc.,  which  vary  in  amounts  according  to  temperature,  rate  of  heating,  and  kind 
of  coal  used.  There  has  been  quite  a lot  of  theorizing  among  coal  investigators 
as  to  what  the  primary  products  of  decomposition  of  each  of  tnese  main  constit- 
uents is  when  the  coal  is  carbonized.  And  on  this  question  they  have  disagreed, 
sometimes  very  widely. 

First  we  will  take  up  a discussion  of  the  work  of  Cross  and  Bevanl,  who 
are  probably  the  most  prominent  investigators  of  cellulose  today.  "By  the  dir- 
ect action  of  heat  upon  celluloses,  aromatic  hydrocarbons  and  phenols  are  obtain- 
ed in  small  quantities.  The  main  products  are:  (1)  gases;  CO^,  CO,  and  CH4, 

(2)  liquids;  water,  acetic  acid,  furfural,  methyl  alcohol,  and  small  quantities 
of  hydrocarbons  and  phenols,  (3)  solids;  paraffins,  and  aromatic  hydrocarbons  in 
small  amounts,  and  residual  charcoal.  The  proportions  of  each  vary  with  the 
conditions  of  distillation,  chiefly,  rapidity  of  heating,  and  maximum  temperature 
attained.  In  the  recent  investigations,  in  which  these  conditions  have  been 
carefully  regulated,  cellulose  has  been  used  in  a broad  sense,  and  the  destruct- 

1.  Reasearches  on  Cellulose.  Cross  and  Bevan 


2 


ive  distillation  of  cellulose  has  included  wood.”  They  obtained  35$  of  the  orig- 
inal sample  as  charcoal,  about  50$  as  distillate,  and  about  15$  as  gas;  50$  of 
this  gas  being  C02,  and  35$  of  it  00.  The  aqueous  distillate  contained  6$  acetic 
acid,  30$  methyl  spirit,  and  the  remainder,  tar. 

Finely  divided  filter  paper  was  distilled  in  quantities  of  1 lqg.  from  a 
copper  retort  by  Erdmann  and  Schaeffer^-.  The  heating  was  continued  about  two 
hours.  The  distillate  was  passed  through  a train  of  vessels  cooled  by  air, 
water,  and  liquid  air,  in  the  order  given.  The  paper  contained  35$  of  fat  which 
gave  rise  to  the  palmitic  acid  found  in  the  distillate.  The  uncondensed  gases 
contained:  co2,  CO,  CH4,  Hg,  and  N2.  The  portion  condensed  by  liquid  air  con- 
sisted of  COo,,  unsaturated  hydrocarbons,  and  acetone.  The  tar  amounted  to  about 
4$  of  the  paper.  The  aqueous  portion  of'  the  distillate  contained  H2S,  HCHO,  fur- 
furaldehyde,  maltol,  hydroxymethyl- furfuraldehyde , and  valeroacetone. 

Klason,  Heidenstam,  and  Norlin2  distilled  cellulose  to  500°  C.  leaving  a 
char  resembling  bituminous  coal,  acetic  acid,  acetone,  and  only  traces  of  methyl 
alcohol.  The  gases  were  15$  of  the  cellulose,  and  consisted  of  C02,  CO,  CH4, 
and  C^Hg.  No  hydrogen  nor  any  of  the  aromatic  hydrocarbons  were  produced. 

Bantlin3  carbonized  pure  cellulose,  and  observed  the  following  data. 

The  evolution  of  gas  begins  at  about  140°  - 160°  C.,  and  at  this  point  C02  pre- 
dominates. This  condition  continues  to  a point  somewhere  between  350°  C.  and 
4000  C.  when  the  proportions  change,  and  the  carbon  dioxide  begins  to  fall  off. 

At  the  5000  mark  the  evolution  of  C02  is  practically  ended.  Klason,  Heidenstam, 
and  Norlin  observed  a point  of  exothermic  heat  at  270°  C.  Bantlin  did  not  ver- 
ify this  statement.  In  the  table  below  is  given  a summary  comparison  of  the 
work  of  Klason,  Heidenstam,  and  Norlin,  and  Sacharoff  and  Bantlin.  Each  used  a 
temperature  of  5000  C. 

1.  Ber.  43  2398  2406  (1910) 

2.  Cham.  Abstracts  2:  3280  (1908) 

3.  Jour,  ftfr  Gasbeleuchtung  57  1914  pp.  33  - 41 


. 


3 


Products 

KLason,  Heidenstam 
and  ITorlin 

Sacharoff 

Bant 1 in 

Solids  and  liquids 

charcoal 

38.82% 

32.05% 

32.97 % 

water 

34.52 

31.17 

31.67 

tar 

4.18 

5.46 

3.25 

acetic  acid 

1.39 

4.27 

3.28 

aldehyde 

5.14 

8.91 

5.82 

ketone 

0.07 

0.50 

0.11 

Oases 

co2 

10.35 

12.71 

11.26 

Ethylene  series 

0.17 

0.17 

0.24 

h2 

0.01 

0.02 

CO 

4.15 

3.27 

4.78 

ch4 

0.30 

0.35 

0.27 

0.48 

0.68 

100.00 

100.00 

100.00 

An  analysis  of  Bant 1 in’s  gas  was  as  follows: 


carbon  dioxide 

14.98% 

oxygen 

1.64 

unsaturated  series 

2.72 

aromatics 

hydrogen 

4.95 

carbon  monoxide 

47.21 

ethane 

3.30 

methane 

16.23 

nitrogen 

8.97 

100.00 


H.  Soilings  and  Wm.  CotrtA  found  that  cellulose  shows  a strong  exothermic 
reaction  starting  at  345°  C.,  hut  this  is  very  much  weakened  in  dehydrated  cell- 
ulose and  lignite  and  absent  in  coal.  ”It  is  presumably  connected  with  the  loss 
of  hydroxyl  groups  and  consequent  condensation  in  the  residue.” 

Burgess  and  Wheeler2,  from  the  results  of  their  work  on  coal,  drew  the 
following  conclusion:  ’’That  coal  is  made  up  of  two  distinctly  different  parts 

or  classes  of  compounds  of  different  degrees  of  ease  of  decomposition,  the  least 
stable  yielding  paraffin  hydrocarbons  and  no  hydrogen,  and  the  other  decomposing 
with  greater  difficulty,  and  yielding  hydrogen  and  the  oxides  of  carbon”. 

I.  Jour,  of  the  Chem.  Soc.  107,  pp.  1106  - 1115 

2.  Jour,  of  the  Chem.  Soc.  97,  pp.  1017  - 1035  (1910) 


. 

• 

. 

4 

Porter  and  Taylor^,  two  American  investigators,  do  not  agree  with  the 
above  idea  that  the  rapid  increase  in  the  yield  of  hydrogen  marks  the  end  of  the 
decomposition  of  the  less  stable,  paraffin  yielding  resinic  constituent  and  the 
beginning  of  the  decomposition  of  the  hydrogen  yielding  cellulosic  constituent. 

They  believe  that  the  first  decomposition  of  any  type  of  coal  as  the  temperature 
is  raised  is  the  breaking  down  of  certain  oxygen-bearing  substances,  related  to 
cellulose,  from  which  water  of  decomposition,  and  the  oxides  of  carbon  is  produced. 
Other  decompositions  producing  paraffin  hydrocarbons,  both  liquid  and  gaseous, 
begin  at  an  early  stage.  Whether  or  not  such  decompositions  become  the  predomin- 
ating type  below  500°  C.  depends  upon  the  character  of  the  coal,  and,  as  a rule, 
the  higher  the  oxygen  in  the  coal,  the  less  will  be  the  proportions  of  hydrocar- 
bons in  the  tar  and  volatile  matter.  In  the  case  of  a sub-bituminous  coal  the 
carbon  dioxide,  water  yielding  reaction  predominates  up  to  450°  C.  Secondary 
decompositions  occur  easily  at  730°  C.  and  above,  and  the  liquid  hydrocarbons  are 
broken  down  to  give  hydrogen,  methane,  ethane,  ethylene,  other  hydrocarbons,  and 
carbon.  They  also  believe  that  the  cellulosic  derivatives  decompose  more  easily 
than  the  resinic  and  yield  water,  oxides  of  carbon,  and  hydro carbons,  giving  less 
of  the  first  the  more  saturated  they  are.  The  resinous  derivatives  decompose 
on  moderate  heating  so  as  to  yield  principally  the  paraffin  hydrocarbons,  and  prob- 
ably hydrogen  as  a direct  product. 

3.  Outline  of  the  present  investigation. 

It  has  been  the  object  of  this  investigation  to  obtain  the  primary  pro- 
ducts of  decomposition  without  having  any  secondary  decomposition  take  place  due 
to  the  products  passing  over  surfaces  heated  to  a higher  temperature  than  that  at 
which  they  were  evolved. 

A study  of  the  products  of  the  destructive  distillation  has  envolved  the 
following  points: 

(a)  Preparation  of  pure  cellulose,  and  as  nearly  as  possible  the 

1.  Tech.  Paper  Ho.  140,  U.  S.  Bureau  of  Mines. 


. 


' 


5 


cellulosic  derivatives  of  wood  and  coal. 

(b)  Determination  of  tne  we ignis  ana  volumes  ox  one  prouucis  of 
tne  ux3oxflaoxun. 

(c)  Ultimate  analysis  of  the  starting  materials. 

(d)  Analysis  and  calculation  of  the  total  yield  of  the  gases  ev- 
olved. 

(e)  Regulation  of  the  rate  of  heating,  and  the  temperature  attained 
during  the  caroonizatiun,  ana  the  noting  of  the  temperature  at  which  any  active 
chemical  reaction  tabes  piace  witnin  the  material  being  carbonized. 

II.  Experimental 

1.  Apparatus. 

A diagram  or  tne  apparatus  which  was  used  in  this  investigation  is  shown 
in  Fig.  1.  The  retort  was  of  Pyrex  tubing,  and  nad  a sligntiy  inclined  delivery 
tube  near  the  top,  and  a tube  near  tne  Dot  tom  for  passing-  nitrogen  into  the  appar- 
atus. The  retort  was  closed  at  the  top  by  a rubber  stopper  carrying  a Pyrex 
tube  sealed  at  the  lower  end.  This  tube  extended  down  almost  to  the  bottom  of 
the  retort,  and  in  it  was  placed  a 510  degree  thermometer.  The  rubber  stopper 
was  protected  from  the  heat  by  two  aluminium  discs  placed  around  the  tube  which 
held  tne  thermometer  near  the  top  of  the  retort.  The  bottom  of  the  retort  was 
covered  witn  glass  wool  to  prevent  the  loss  of  sample  through  the  tube  at  the 
bottom. 

The  test  from  4500  C.  to  750°  C.  was  made  in  an  iron  retort  already  in 
the  laboratory.  It  consisted  of  a capped,  two-inch  iron  pip©  containing  a ther- 
mocouple tuDe  extending  down  aimost  to  tne  bottom  of  the  retort.  The  retort  was 
fitted  with  a l/8  inch  pipe  delivery  tube  at  the  top,  and  a l/a  inch  tube  at  the 
bottom  for  the  introduction  of  nitrogen.  The  pipe  was  cut  in  two,  and  fitted 
with  a flange  union  which  was  bolted  together  with  l/2  inch  bolts,  and  sealed  by 

an  asbestos  gasket.  The  retort  was  found  to  be  gas-tight  by  testing  same  under 


, . 

. 


water 


6 

The  inside  and  outside  temperatures  were  measured  by  a chromel-alumel 
thermocouple  which  was  standardized  against  molten  lead  and  tin.  It  was  found 
to  be  sensitive  and  accurate  to  4°  C. 

The  retort  was  heated  by  a ni-chrome  wound,  electric  resistance  furnace 
which  was  insulated  and  packed  with  asbestos,  and  sil-o-cell.  An  external  res- 
istance was  used  to  regulate  the  temperature. 

Nitrogen  gas  was  passed  into  the  apparatus  from  a 12  liter  aspirator 
bottle.  It  was  dried  by  passing  through  a sulfuric  acid  wash  bottle. 

The  100  c.  c.  distilling  flask  at  the  end  of  the  side  arm  delivery  tube 
collected  the  water,  tar,  and  oil. 

Next  in  line  was  a calcium  chloride  tube  with  glass  wool  in  it  to  catch 
the  tar  fog.  After  that  came  a calcium  chloride  tube  wnich  dried  the  gas. 

A mercury  manometer  next  indicated  the  pressure  in  the  retort. 

A U-tube  half  full  of  glass  beads  and  10$  sulfuric  acid  served  to  remove 
any  ammonia  and  to  indicate  when  gas  was  coming  over. 

The  gas  was  then  collected  in  a 12  liter  aspirator  bottle  over  saturated 
salt  solution.  The  Dottle  was  graduated  to  25  c.  c.,  ana.  the  gas  was  measured 
under  atmospheric  pressure  after  each  run  by  means  of  a second  aspirator  bottle 
which  served  as  a levelling  Dottle. 

2.  Operation. 

Before  each  test  the  apparatus  was  swept  out  with  nitrogen,  the  air  ex- 
hausted uy  a vacuum  at  the  delivery  end,  and  the  nitrogen  let  in  to  take  the  place 
of  the  exhausted  air.  The  sample  used  was  33  l/3  grams.  The  collecting  bottles 
were  hooked  on  by  means  of  a rubber  tube,  and  the  current  turned  on.  The  level- 
ing bottle  v/as  kept  at  a slightly  lower  level  than  the  collecting  bottle  through- 
out the  run  so  as  to  maintain  a slight  vacuum,  and  thus  remove  the  gases  as  soon 
as  they  were  formed.  The  retort  was  heated  at  practically  the  same  rate  each 
time,  the  inside  alv/ays  being  about  75°  C.  cooler  than  the  outside  till  the  final 

temperature  was  reaoned.  When  the  final  temperature  was  attained  it  v/as  held  by 


. 


* 


■ 


. 


. 


7 


means  of  the  external  resistance  till  all  the  gas  was  expelled  from  the  material 
in  the  retort.  The  complete  run  required  from  2 to  3jr  hours  depending  upon  the 
material  used,  and  the  final  temperature  attained.  At  the  end  of  each  run  the 
apparatus  was  swept;  out  with  one  liter  or  dry  nitrogen  to  insure  tne  removal  of 
the  last  traces  of  evolved  gas.  The  stopcock  on  the  collecting  bottle  was  then 
closed,  the  bottles  leveled  and  the  reading  taken.  The  inside  and  outside  temp- 
eratures were  read  by  thermometers.  A piece  of  asuestos  uoard  with  a hole 
through  which  the  retort  passed  covered  the  top  of  tne  furnace.  The  portion  of 
the  retort  extending  out  of  the  furnace  was  wrapped  with  asbestos. 

3.  Determination  and  Analysis  of  Products. 

Oil,  tar,  and  water  were  determined  by  weighing  the  flask  before  and 
after  tne  run. 

The  residue  was  determined  by  weight. 

Gas  was  collected  and  measured  as  described  above.  It  was  analyzed  in 
a modified  Orsat  apparatus  of  the  type  in  use  at  the  University  of  Illinois. 

First  COg  was  removed  by  40$  KOH,  0g  was  taken  out  by  passing  the  gas  into  alk- 
aline pyrogallol  solution.  The  ethylene  series  was  taken  out  oy  bromine  water, 
the  aromatics  by  absorption  in  fuming  H2SO4,  hydrogen  and  carbon  monoxide  by  pass- 
ing the  gas  through  a copper  oxiae  furnace  heated  to  300°  C.  The  H2  was  oxidized 
to  HgO,  and  determined  by  the  amount  of  contraction,  and  the  CO  was  burnt  to  COg, 
which  was  absorbed  in  the  KOH  pipette.  Finally  the  metiiane  series  was  burned 
with  an  excess  of  oxygen  in  a slaw  combustion  pipette,  and  the  volume  of  methane 
and  ethane  determined  by  the  method  of  Parr. 

2 x the  contraction  - CO?  m volume  (of  methane  and  ethane) 

3 

CO? 

n I vol.  (n  - 1)  x vol.  = ethane  vol.  - ethane  - methane. 

Nitrogen  was  determined  by  difference. 

Due  to  the  small  amounts  of  oil  and  tar  obtained  no  analysis  was  made  of 

them. 


■ 


8 

4.  Preparation  of  Materials. 

(a) .  Preparation  of  pure  cellulose. 

300  grams  of  cotton  batting  v/ere  purified,  and.  freed,  from  resins  and  oils 
by  soiling  in  a 5 liter  flask  with.  5 $ CaOH,  and  then  neutralizing  with  HOI.  The 
product  was  then  thoroughly  washed  and  dried.  This  is  after  the  method  of  Cross 
and  Bevan.  The  pure  product  was  stored  in  a sealed  jar  under  nitrogen. 

(b) .  Preparation  of  Cellulosic  Residues  of  Coal. 

200  grains  of  finely  powdered  coal  were  extracted  for  40  -50  hours  with 
one  liter  of  10$  alcoholic  K0H  tinder  a reflux  condensor.  The  flask  was  heated 
by  a water  bath.  The  contents  of  the  flask  were  then  allowed  to  cool,  and  the 
residue  was  filtered  off,  and  washed  with  alcohol,  water,  and  ether  in  a Buchner 
funnel.  It  was  then  transferred  to  a large  evaporating  dish  and  the  entrapped 
K0H  neutralized  with  dilute  HC1.  The  product  was  again  filtered*  and  washed  with 
alcohol  and  water.  It  was  then  dried  at  105°  C.  under  nitrogen,  and  stored  in  a 
sealed  jar  under  nitrogen. 

The  filtrate  containing  tne  extract  was  then  concentrated  by  distilling 
off  most  of  the  alcohol  and  water.  It  was  then  neutralized  and  precipitated  by 
dilute  HC1.  The  extract  v/as  filtered,  dried,  and  weighed.  This  method  of  ex- 
traction saponified,  and  dissolved  the  resinous  material  from  the  coal  leaving  the 
cellulosic  materials  behind.  It  did  not,  however,  alter  the  appearance  of  the 
coal. 

The  Utah  coal  residue  from  diphenyl  ether  extraction  was  obtained  from 
J.  R.  Smith  who  was  working  in  the  same  laboratory  at  the  time  of  this  investi- 
gation. 

The  oak  shavings  were  prepared  by  planing  down  an  oak  board  into  small 
shavings.  They  were  then  thoroughly  air-dried. 

The  4b0  degree  cellulose  was  prepared  by  heating  in  the  retort  the  pure 
cellulose  to  450°  C.  until  all  the  gaseous  products  were  expelled.  It  was  at 

once  transferred  to  the  iron  retort,  and  carbonized  up  to  750  degrees  C. 


. 


' 


9 


The  following  are  the  ultimate  analyses  of  the  materials  used  in  the  in- 


vestigation: 


Pure 

Cellulose 
(as  rec'd) 

450° 

Cellulose 
(as  rec'd) 

Utah 

Residue 

(dry) 

Zeigler 
Residue 
(as  rec'd) 

Lignite 
Residue 
(as  rec'd) 

Oak 

Shavings 
(as  rec'd) 

Carbon 

46.82 

71.52 

71.71 

69.45 

67.08 

49.04 

Hydrogen 

5.83 

5.52 

5.84 

4.45 

2.14 

5.85 

Oxygen 

43.02 

14.31 

13.96 

14.66 

14.12 

35.38 

Nitrogen 

0.00 

0.00 

1.32 

1.40 

1.62 

0.11 

Sulfur 

0.00 

0.00 

0.45 

0.71 

0.86 

0.56 

Ash 

0.48 

1.14 

6.72 

6.18 

3.59 

0.38 

Moisture 

— a«.a£. 
100.00 

4.20 

100.00 

0.00 

100.00 

3.15 

100.00 

10.56 

100.00 

8.68 

100.00 

B.  T.  U. 

7,092 

12,465 

12,965 

11,765 

10,050 

8,062 

. 


. . 


. 


III.  Results. 

Table  I. 

Carbonization  of  Pure  Cellulose 
Degrees  centigrade  250  300  350 

400 

450 

10 

Percentages  COg 

59.14 

53.20 

70.40 

60.80 

54.05 

°2 

13.41 

10.88 

1.15 

1.15 

.90 

CH2n 

.42 

1.48 

1.73 

1.95 

Aromatics 

H2 

27.45 

35.50 

25.22 

34.73 

37.20 

CO 

. 

CD 

IV) 

.15 

1.50 

ch4 

.93 

1.44 

5.40 

100.00 

100.00 

100.00 

100.00 

100.00 

Table 

II. 

Degrees  centigrade 

250 

300 

350 

400 

450 

Volume  gas  in  c.  c.  C02 

418.0 

1014.0 

1785.0 

1875.0 

1825.0 

per  100  gr. 

of  sample.  q 

94.5 

207.0 

37.3 

35.6 

30.3 

°nH2n 

8.0 

29.0 

53.4 

65.6 

Aromatics 

H2 

201.0 

677.0 

639.0 

1073.0 

1253.0 

CO 

20.8 

4.5 

50.5 

CH4 

24.9 

44.5 

182.0 

713.5 

1906.0 

2566.0 

3086.0 

3406.4 

Table  III. 

Degrees  centigrade 

250 

300 

350 

400 

450 

Liquid  Distillate,  grams 

8.4 

24.9 

31.5 

33.1 

36.1 

Charred  Residue,  grams 

72.2 

54.0 

46.6 

42.1 

37.6 

. 


. 


• 

, 


Table  17 


Carbonization  of  450°  Cellulose 
Temperature  450°  - 750°  C. 


% Composition 

COg 

16.58 

°2 

3.62 

7.10 

arom.  Hg 

0.00  38.00 

ce 

10.88 

ch4 

22.72 

CEH6 

1.10 

7ol.  per  100  g. 

2240 

488 

959 

5130 

1470 

3060 

148 

Wt.  of  water  and  tar  per  100  gram  of  sample 5.0  grams 

Total  volume  of  gas 13,495  o.  c. 

Table  7. 

Carbonization  of  Zeigler  111.  Coal  after  Extraction  with  10%  Alcoholic  KOH 

Gas  Analysis  (nitrogen  free  basis) 

Percentage  Composition 


Degrees  C. 

300 

350 

400 

450 

o 

o 

ro 

84.30 

77.60 

66.45 

65.30 

02 

2.82 

3.87 

0.79 

2.74 

cnE2n 

1.30 

2.00 

3.77 

4.18 

arom. 

0.32 

h2 

1.08 

7.46 

6.43 

5.75 

CO 

5.30 

4 . 48 

7.02 

5.82 

ch4 

1.30 

2.00 

6.43 

7.38 

02h6 

3.90 

3.59 

6.79 

8.93 

Totals 

100.00 

100.00 

100.00 

100.00 

Table  V.  (cont’d) 


Volume  of 

gas  in  c. 

c.  per  100 

grams 

Degrees  C 

. 300 

350 

400 

450 

C02 

1185.0 

1550.0 

1860.0 

2200.0 

°2 

39.5 

79.3 

22.1 

90.5 

cnH2n 

18.2 

41.0 

105.7 

138.0 

Arom. 

8.9 

h2 

15.1 

153.0 

180.0 

192.0 

CO 

74.3 

92.0 

195.0 

192.0 

ch4 

18.2 

41.0 

180.0 

244.0 

°2K6 

54.6 

72.6 

190.0 

295.0 

Totals 

1404.9 

2028.9 

2791.7 

3329.5 

wt. 

of  water  and  tar 

4.0 

5.0 

5.0 

5.5 

per 

100  grams 

Wt. 

of  residue  in  gr 

. 90.0 

87.0 

85.0 

84.0 

* 

Table  VI 


Carbonization  of  Castle  Gate  Utah  Coal  after  extraction 
with  10%  alcoholic  KOH. 

Gas  Analysis  (nitrogen  free  basis) 
Percentage  by  volume 


Degrees  C 

. 300 

350 

400 

450 

C02 

65.43 

55.90 

54.00 

49.90 

°2 

11.40 

23.93 

4.24 

3.73 

cnH2n 

0.42 

1.48 

6.52 

5.37 

Arom. 

0.43 

1.14 

0.61 

0.67 

H2 

18.24 

12.96 

9.03 

8.20 

CO 

2.28 

2.00 

3.30 

3.18 

0H4 

1.80 

2.59 

14.60 

18.40 

c2e6 

9.50 

10.70 

Totals 

100.00 

100.00 

100.00 

100.00 

Vol.  of  gas  in  c. 

c.  per  100 

gr. 

Degrees  C, 

. 300 

350 

400 

450 

002 

393.0 

672.0 

973.0 

1100.0 

°2 

68.4 

287.0 

76.4 

82.1 

CnH2n 

2.5 

17.8 

118.0 

118.2 

Arom. 

2.6 

13.7 

13.8 

14.7 

H2 

109.5 

155.6 

163.0 

181.0 

CO 

13.7 

24.0 

59.4 

70.0 

"ch4 

10.8 

31.1 

263.0 

405.0 

°2H6 

171.0 

236.0 

Totals 

601.5 

1201.2 

1867 . 6 

2209.0 

wt. 

of  water  and  tar 

per 

100  grams 

3.0 

5.0 

8.0 

8.0 

Wt. 

of  residue 

92.5 

90.0 

86.0 

84.5 

. 

. 

14 


Table  VII. 

Carbonization  of  Air  Dried  Oak  Shavings 
Gas  Analysis  (H2  free  basis) 
Percentage  composition 


Degrees  C. 

350 

400 

450 

0 

0 

tV3 

64.10 

53.40 

52.70 

°2 

0.92 

0.80 

0.31 

CnHsn 

1.71 

1.80 

1.84 

Arom. 

0.26 

0.26 

0.31 

H2 

19.55 

27.40 

26 . 33 

CO 

13.20 

12.69 

10.71 

ch4 

0.39 

3.75 

7.16 

°2=6 

0.62 

Totals 

100.00 

100.00 

100.00 

Vol. 

of  gas  in  c. 

c.  per 

100  gr. 

Degrees  C. 

350 

400 

450 

C02 

5620.0 

5280.0 

6325.0 

350 

400 

-jQ 

°2 

80.6 

79.3 

37.2 

cnH2n 

149.7 

179.3 

221.0 

Arom. 

22.8 

25.8 

37.2 

1607.0 

2720.0 

3160.0 

CO 

1157.0 

1258.0 

1287.0 

ch4 

34.2 

372.0 

863.0 

C2H6 

74.5 

Totals 

8771.3 

9914.4 

12004.9 

V/t.  of  water  and  tar 

per  100  grams 

26.5 

37.0 

42.0 

V/t  • of  Residue 

70.2 

61.0 

51.4 

15 

Table  VIII. 

Carbonization  of  a Weathered  Western  Lignite  after 

extraction  with  a 10/£  alcoholic 

KOH  solution. 

Gas  analysis  (U2  free  basis) 

Percentage  composition 

Degrees  C 

. 350 

400 

450 

co2 

86.50 

80.90 

73.80 

°2 

2.49 

1.92 

0.74 

^n^2n 

1.03 

1.62 

1.93 

Arom. 

0.29 

0.31 

0.59 

H2 

2.64 

5.20 

4.10 

CO 

7.05 

4.00 

8.30 

oh4 

2.15 

3.42 

=2*6 

3.20 

7.12 

Totals 

100.00 

100.00 

100.00 

Volume  of 

gas  in  c.  c. 

per  100  gr. 

Degrees  C 

. 350 

400 

450 

co2 

3635.0 

3885.0 

4430.0 

°2 

104.0 

99.2 

44.4 

CnH2n 

43.3 

77.7 

116.0 

Aram. 

12.2 

14.9 

35.4 

h2 

110.0 

250.0 

246.0 

CO 

296.0 

192.0 

500.0 

ch4 

105.3 

205.0 

c2H  6 

154.0 

427.0 

Totals 

4202.1 

4775.1 

6003.8 

wt. 

of  water  and 

tar 

per  100  grains 

14.0 

16.0 

19.0 

Wt. 

of  residue 

82.5 

79.0 

74.2 

. 


CARBOK X I OX'i  OX1  XXJX.X  Cii»X XU X Ol>— i • 


QAXIBOI;  X i.jii.'j.1  IOIJ  0^  /juii  XltXuxR  G OiiXi  iiLSS  XX)G^-*  • 


CAKBODIZAT I OH  OF  UTAII  GOAL  RESIDUE. 


-iso 


d>6o  © 


GARB  Oil!  2AT I OU  OR  LIGATED  RESIDUE* 


16 


Table  IX 

Extraction  of  Coal  with  10 % alcoholic  KOH 
Zeigler  111.  Coal  8.0%  extraction 

Western  lignite  11.0$  extraction 

2.  Discussion  of  results. 

The  results  of  the  work  are  given  in  the  preceding  tables  and  graphs. 

The  gas  analyses  have  been  reduced  to  the  nitrogen  free  basis  in  order  to  bring 
out  the  relative  amounts  of  the  various  constituents  more  sharply  and  to  elimin- 
ate the  error  incurred  by  determining  nitrogen  by  difference. 

In  the  case  of  cellulose,  the  first  evolution  of  gas  occured  at  150°  - 
165°  C.  This  gas  was  principally  carbon  dioxide,  hydrogen,  and  a small  amount 
of  occluded  oxygen.  Water  in  appreciable  amounts  began  to  come  over  about  190° 
C.,  which  point  marks  the  formation  of  water  of  decomposition.  Bantlin  observed 
the  first  evolution  of  gas  at  about  140°  C.  Near  300°  C,  the  evolution  of  COg 
took  a decided  jump,  and  the  hydrogen  slowed  down  a little.  It  was  at  this 
point  that  the  presence  of  ethylene  in  the  gas  was  first  noted.  At  350°  C.  the 
carbon  dioxide  had  slowed  down  to  a gradual  rise,  while  the  hydrogen  had  begun  to 
increase.  Here  the  occluded  Og  was  very  small,  probably  due  to  the  fact  that  it 
was  combining  with  the  free  car Don.  Bantlin  observed  this  point  near  350°  C. 

where  the  CO^  of  the  gas  grows  less.  At  350°  C.,  carbon  monoxide  and  methane 
were  first  determined.  At  400°  G,  the  methane  began  to  rise,  and  there  was  pro- 
bably some  ethane  given  off  here  but  it  was  too  small  a quantity  to  be  determined. 
At  450°  C,  the  carbon  dioxide  was  slumping  a little,  but  had  not  nearly  disappear- 
ed as  was  found  by  Bantlin;  the  hydrogen  was  growing  less,  and  the  methane  and 
carbon  monoxide  were  rising. 

The  data  on  the  test  from  450°  - 750°  C.  shows  that  COg  had  sunk  16.58%, 
and  the  CO  was  up  to  10.88%.  Methane  was  up  to  22.72%,  and  the  hydrogen  38.00%. 
This  verifies  the  statement  of  several  other  investigators  that  CO  and  H£  begin 


17 


to  dominate  the  field  at  this  point. 

The  rapid  increase  in  the  carbon  dioxide  between  300°  C.  and  350°  C, 
corroborated  the  statement  of  Hollings  and  Cobb  that  there  is  an  exothermic  re- 
action at  this  poiht,  and  a change  in  the  type  of  decomposition  which  occurs. 

The  aqueous  distillates  were  analyzed  qualitatively,  and  found  to  contain 
water,  methyl  alcohol,  acetone,  and  some  tarry  matter.  A quantitative  estimation 
of  these  products  was  not  made  due  to  the  small  amounts  of  eacn  yield.  Klason, 
Heidenstam,  and  Norlin  found  no  hydrogen  nor  metixyi  -.loonoi  wnic-u.  is  ausoiuoeiy 
contrary  to  one  results  ox  tais  woric.  Bantlin  obtained  a great  deal  more  caroon 
monoxide,  and  about  naif  as  much  hydrogen. 

The  test  from  4t>00  C.  to  730°  C is  significant  because  of  the  small 
amount  of  water  or  tarry  matter  evolved.  It  shows  that  the  principal  decompos- 
itions of  cellulose  occur  below  500°  C* 

In  the  carbonization  of  the  coal  residues,  CO2  was  the  predominating  gas 
throughout.  In  the  Zeigler  coal,  CO  and  CH4  snowed  no  rapid  rise.  Hydrogen 
arose  abruptly  from  300°  C.  to  350°  C,  and  then  almost  stopped.  The  ethylene 
series  began  to  rise  rapidly  at  350°  C.  Ethane  rose  gradually  throughout. 

In  the  Utah  coal,  residue  Kg  rose  gradually.  CH4  jumped  up  at  350°  C. 
Ethane  did  not  appear  in  any  amount  till  400°  C.  Ethylene  series  rose  till  400° 
C,  and  then  practically  ceased.  The  aromatic  hydrocarbons  were  so  slight  that 
they  were  not  plotted  on  the  graph. 

In  the  case  of  the  lignite  residue,  the  C0o  was  unusually  high,  indicat- 
ing that  the  coal  was  highly  weathered.  Hg  rose  rapidly  from  3500  - 400°  C. 

CH^  appeared  at  400°  C.,  and  rose  rapidly.  The  ethylene  series  showed  a gradual 
rise  throughout.  Aromatics  were  plotted  in  this  case,  and  increased  steadily  to 
450°  C.  CO  and  ethane  increased  slowly.  The  lignite  coal  residue  gave  off  more 
gas  than  either  of  the  other  two.  Nowhere  in  the  literature  is  tnere  any  absol- 

ute data  on  the  carbonization  of  a coal  residue.  Burgess  and  Wheeler  state  that 

the  cellulosic  constituent  decomposes  with  difficulty,  but  it  was  found  in  tiie 


. 


18 

present  investigation  that  they  decompose  with  ease  throughout  the  range  of  temp- 
eratures used.  Porter  and  Taylor  believe  that  the  first  decomposition  in  coal 
carbonization  is  the  breaking  down  of  the  oxygen  bearing  ceilulosic  derivatives 
from  which  water  of  decomposition,  and  the  oxides  of  carbon  are  the  main  products. 
This  is  undoubtedly  true.  However,  their  statements  would  lead  one  to  believe 
that  they  think  most  of  the  hydrogen  produced  in  the  early  decompositions  come 
from  the  resinic  portions.  Prom  a study  of  tne  tables  and  graphs  it  is  evident 
that  hydrogen  is  produced  in  appreciable  quantities  from  the  decomposition  of  the 
ceilulosic  substances,  and  also  some  of  the  hydrocarbons. 

Carbon  dioxide  predominates,  also,  in  the  carbonization  of  the  oak  shav- 
ings. Here  the  quantity  of  gas  evolved  was  much  larger  than  that  from  any  other 
material  worked  with.  Hg,  CH4,  ethylene,  and  aromatics  rose  gradually.  CO 
remained  practically  constant.  Ethane  did  not  appear  until  450°  C.,  and  then 
only  in  small  amounts.  The  quantity  of  aqueous  distillate  was  greater  in  the 
case  of  the  oak  shavings,  cellulose  came  next,  and  che  yield  of  this  product  from 
the  three  coal  residues  was  practically  the  same. 

In  several  instances  in  this  work,  one  will  notice  that  the  amount  of  a 
gas  given  off  at  one  temperature  is  about  the  same,  and  sometimes  even  less  than 
that  given  off  at  a lower  temperature.  This  is  due  to  slight  variations  in  the 
rate  of  heating  to  the  different  degrees  of  exhaustion  of  atmospheric  oxygen  from 
the  apparatus,  and  in  the  case  of  the  coal  residues,  to  unavoidable  oxidation  of 
certain  portions  of  them  in  handling,  wasning,  and  drying. 

The  figures  given  in  this  data  are  by  no  means  absolutely  accurate  ex- 
pressions of  the  amounts  of  each  substance  which  will  be  evolved  in  carbonization. 
Several  tests  were  made  to  discover  whether  or  not  absolute  checks  could  be  made 
on  a carbonization  at  the  same  final  temperature,  and  it  was  found  that  only 
approximate  checks  were  possible.  Better  checks,  no  doubt,  could  be  made  by  us- 
ing a larger  apparatus,  and  larger  quantities  of  materials. 


1 


, 


19 

17.  Summary  and  Conclusions. 

The  principal  gas  in  the  carbonization  of  cellulose,  and  cellulosic  res- 
idues up  to  450°  C.  is  CC>2.  Hydrogen  is  produced  in  appreciable  amounts  from 

all  these  materials,  but  more  so  from  the  pure  cellulose,  than  from  its  degrada- 
tion products.  Paraffin, hydrocarbons,  chiefly  methane,  are  evolved  from  pure 
cellulose,  and  as  we  procedd  down  the  list  of  cellulosic  materials  which  have  been 
altered  more  and  more  the  methane  gives  way  to  increasing  yields  of  ethane,  and 
probably  some  of  the  higher  members  of  the  series.  Aromatic  hydrocarbons  are  not 
produced  in  the  carbonization  of  cellulose.  They  appear  in  the  gases  from  wood, 
and  lignite,  and  then  decrease  in  the  gases  from  bituminous  coals.  Here  tney 
appear  as  higher  members  of  the  series,  and  in  the  tar.  This  might  indicate 
that  cellulose  in  its  cnange  into  the  cellulosic  derivatives  of  bituminous  coal 
is  arranged  inco  compounds  which  give  aromatic  hydrocarbons  on  carbonization. 

Prom  the  yields  of  aqueous  distillates,  it  is  evident  tnat  cellulose  and  wood  cel- 
lulose are  more  hydrated  tnan  hie  coal  residues. 

The  following  conclusions  have  been  drawn: 

1.  That  tne  cellulosic  constituent  is  being  decomposed  throughout  the 
coicing  process,  and  is  responsible  for  most  of  the  hydrogen  of  the  gas,  the  car- 
bon dioxide,  and  a large  part  of  the  hydrocarbons. 

2.  That  there  is  a point  at  about  350°  C.  in  which  the  decomposition  of 
the  pure  cellulose  rapidly  increases,  and  new  types  of  decomposition  begin. 

3.  That  the  products  of  the  more  highly  altered  cellulosic  materials 
are  of  the  same  series  or  type  as  those  from  the  less  altered  ones. 


